parwei {lmomco} | R Documentation

## Estimate the Parameters of the Weibull Distribution

### Description

This function estimates the parameters of the Weibull distribution given the L-moments of the data in an L-moment object such as that returned by `lmom.ub`. The Weibull distribution is a reverse Generalized Extreme Value distribution. As result, the Generalized Extreme Value algorithms are used for implementation of the Weibull in this package. The relation between the Generalized Extreme Value parameters (xi, α, and kappa) is

kappa = 1/delta mbox{,}

α = β/delta mbox{, and}

xi = zeta - β mbox{.}

These relations are taken from Hosking and Wallis (1997).

### Usage

    parwei(lmom,checklmom=TRUE)

### Arguments

`lmom` | A L-moment object created by `lmom.ub` or `pwm2lmom`.
`checklmom` | Should the `lmom` be checked for validity using the `are.lmom.valid` function. Normally this should be left as the default and it is very unlikely that the L-moments will not be viable (particularly in the tau_4 and tau_3 inequality). However, for some circumstances or large simulation exercises then one might want to bypass this check.

### Value

An R `list` is returned.

`type` | The type of distribution: `wei`.
`para` | The parameters of the distribution.
`source` | The source of the parameters: “parwei”.

### Author(s)

W.H. Asquith

### References

Hosking, J.R.M. and Wallis, J.R., 1997, Regional frequency analysis—An approach based on L-moments: Cambridge University Press.

### See Also

`lmom.ub`, `lmomwei`, `cdfwei`, `quawei`

### Examples

    lmr <- lmom.ub(rnorm(20))
    parwei(lmr)
    lmr <- parwei(lmom.ub(rweibull(3000,1.3,scale=340)-1200))
    str(lmr)

[Package lmomco version 0.92 Index]